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I am replacing the cutters in my jointer and debating between high speed steel and carbide.

What are the advantages and disadvantages of HSS vs carbide jointer blades?

Daniel B.
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  • See related question about helical heads in planers; the same answers apply. – keshlam May 20 '15 at 19:02
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    Mm. I asked two questions because I felt the other was more about the segmented spiral design vs straight blade, and this is aimed at the material the blade is made from. I understand carbide blades can't be made as sharp as HSS? – Daniel B. May 20 '15 at 19:05
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    @keshlam you can get 3 blade cutters in both HSS and carbide – Steven May 20 '15 at 19:05
  • Valid points. But I think I did cover most of the tradeoffs there. Carbide will keep an edge longer but is harder to resharpen and is a larger investment. – keshlam May 20 '15 at 19:16
  • Shall i close this one then, or does it have merit on its own? – Daniel B. May 20 '15 at 19:18
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    I'd vote to keep it open - this is a material choice question, while the other is a design question. I thought we had another question about Carbide vs HSS saw blades, but some quick searching isn't turning one up. – FreeMan May 20 '15 at 19:28
  • Carbide blades came up in one of the answers to my question about gouges, someone suggested using carbide tool inserts to make a gouge. Even if there was, I think there's also a difference between a saw blade and a jointer knife that may make a difference in material choice, too. – Daniel B. May 20 '15 at 19:38

1 Answers1

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All else being equal, anytime you have a choice between HSS (high speed steel) and carbide, you have to consider the tradeoffs.

High-Speed Steel

Advantages:

  • Cheaper up-front
  • Easier to sharpen
  • Less brittle

Disadvantages:

  • Potentially more expensive long-term (depending on application)
  • Wears faster (must be sharpened or replaced more frequently)

Carbide

Advantages:

  • Theoretically more cost-effective long-term (depending on application)
  • More wear-resistant (often praised as lasting 10x as long as HSS)

Disadvantages:

  • More expensive up-front
  • More difficult to sharpen
  • More brittle

When does it matter?

If you're looking at long jointer knives, high-speed steel is a proven material, and if you happen to completely trash your knives by running nails through your machine, the knives aren't very expensive to replace.

If you're looking at a cutterhead with segmented knives or inserts, carbide is a good choice because at worst you'll shatter the inserts that hit the nails.

rob
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  • HSS is easier to sharpen ... can they get comparable edges though, given enough effort on the carbide blade? – Daniel B. May 20 '15 at 19:54
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    From my understanding, it depends on the size of grains in the carbide. Generally you cannot sharpen a carbide cutter quite as sharp as a steel cutter, but as both tools start to dull, the carbide one will hold its edge longer. – rob May 20 '15 at 20:04
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    So far, in my many years in the woodshop and as a machinist, I've handled exactly *one* carbide insert that was as sharp as I can easily get HSS; that one insert was a fine finishing insert specifically for aluminum. I've never seen any carbide inserts in any profile that could match the sharpness of HSS. End mills, yes - they're built differently. Personally, I use HSS jointer & planer knives. I buy the steel once, resharpen & resharpen & resharpen... and it last a *very long time. Buy the carbide, and you end up buying a lot* of it because you can't reasonably sharpen it. – TDHofstetter Sep 07 '15 at 02:45